Consumers often desire skin lightening products that are affordable, safe, stable, and can produce consumer-noticeable skin lightening after routine use. In this regard, consumers may desire skin lightening products to either lighten the color of their skin and/or minimize skin spots or blotchiness. For example, consumers may desire skin lightening agents to counteract fluctuations in skin color brought about by hormonal fluctuations or environmental stressors like UV light.
At least some skin lightening agents work by targeting or influencing one or more of the steps involved in the development of skin color. Human skin color is attributed in part to the outermost layer of skin (i.e. epidermis) where many melanocytes may be located. The synthesis of melanin, pigments that may be dark brown/black or light red-yellow, is a complex process that involves the enzyme, tyrosinase, and can take place within the melanosomes of the melanocytes. These melanosomes may be transferred from the melanocyte to the keratinocytes.
While the effects of certain individual ingredients on skin pigment have been studied to some degree, the role that combinations of ingredients might play in the appearance of skin color appears to be less well studied, including how varying concentrations, ratios and/or combinations of ingredients might affect the pigment of the skin.